The conditions of office environment and perceived evaluation of workers difference by season: Insights from field surveys in summer and winter in Tokyo

Creating a thermal environment where workers can work comfortably is essential for offices. Considering seasonal variations in office environments and gender differences in comfort is essential for improving worker comfort. This study analysed the relationship between the office environment and worker comfort in multiple seasons. Measurement surveys were conducted in 15 offices in 11 buildings in Tokyo in the summer of 2022 and the winter of 2023, and questionnaire surveys were conducted with 56 workers. The results of the measurement data showed that the average indoor air temperature, relative humidity, and CO2 concentration in all offices were respectively 25.3°C, 60.6%, and 556 ppm in the summer, and 24.6°C, 38.6%, and 852 ppm in the winter. Additionally, the neutral temperature for male workers in summer was found to be 26.5°C. Furthermore, male workers tended to feel less comfortable as the air temperature increased in the summer, while female workers tended to feel less comfortable as the air temperature decreased. In addition, seasonal differences in office workers’ sensitivity to the thermal environment were indicated. The results of this study provide fundamental knowledge about the conditions of the office environment and the perceived evaluation of the office environment by workers in multiple seasons.